CVE-2021-47236 json
net: cdc_eem: fix tx fixup skb leak
published 2024-05-21 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-33884
- cvss
- 5.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 13%
- public exploits
- 0
- none known
Summary
In the Linux kernel, the following vulnerability has been resolved:
net: cdc_eem: fix tx fixup skb leak
when usbnet transmit a skb, eem fixup it in eem_tx_fixup(), if skb_copy_expand() failed, it return NULL, usbnet_start_xmit() will have no chance to free original skb.
fix it by free orginal skb in eem_tx_fixup() first, then check skb clone status, if failed, return NULL to usbnet.
Patch / fix
- Linux Linux 4.4.274, 4.9.274, 4.14.238, 4.19.196, 5.4.128, 5.10.46, 5.12.13, 5.13
- linux Debian 14, Debian 13, Debian 12 5.10.46-1
debian advisories DEBIAN-CVE-2021-47236
- linux Ubuntu 18.04 LTS 4.15.0-156.163
- linux Ubuntu 20.04 LTS 5.4.0-81.91
- linux-aws Ubuntu 18.04 LTS 4.15.0-1111.118
- linux-aws Ubuntu 20.04 LTS 5.4.0-1055.58
- linux-gcp Ubuntu 20.04 LTS 5.4.0-1051.55
- linux-kvm Ubuntu 18.04 LTS 4.15.0-1099.101
- linux-kvm Ubuntu 20.04 LTS 5.4.0-1045.47
- linux-azure Ubuntu 20.04 LTS 5.4.0-1056.58
ubuntu advisories UBUNTU-CVE-2021-47236
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- kernel RHEL 8 4.18.0-553.8.1.el8_10
- perf RHEL 8 4.18.0-553.8.1.el8_10
- bpftool RHEL 8 4.18.0-553.8.1.el8_10
- kernel-core RHEL 8 4.18.0-553.8.1.el8_10
- kernel-tools RHEL 8 4.18.0-553.8.1.el8_10
- python3-perf RHEL 8 4.18.0-553.8.1.el8_10
- kernel-modules RHEL 8 4.18.0-553.8.1.el8_10
- kernel-zfcpdump RHEL 8 4.18.0-553.8.1.el8_10
red hat advisories RHSA-2024:4211RHSA-2024:4352
- kernel-rt SLE Micro 5.2, SLE Micro 5.1 5.3.18-150300.211.1
- kernel-source-rt SLE Micro 5.2, SLE Micro 5.1 5.3.18-150300.211.1
- kernel-64kb SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS, Enterprise Storage 7.1 5.3.18-150300.59.164.1
- kernel-syms SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.164.1
- kernel-source SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.164.1
- kernel-default SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Micro 5.2 +5 more 5.3.18-150300.59.164.1
- kernel-preempt SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.164.1
- kernel-obs-build SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS +1 more 5.3.18-150300.59.164.1
suse advisories SUSE-SU-2025:01995-1SUSE-SU-2024:2185-1SUSE-SU-2024:2184-1SUSE-SU-2024:2183-1SUSE-SU-2024:2010-1SUSE-SU-2024:1983-1
- kernel-rt AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
- kernel-rt-kvm AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
- kernel-rt-core AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
- kernel-rt-modules AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
- kernel-rt-debug-kvm AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
- kernel-rt-debug-core AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
- kernel-rt-debug-modules AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
- kernel-rt-modules-extra AlmaLinux 8 4.18.0-553.8.1.rt7.349.el8_10
almalinux advisories ALSA-2024:4352ALSA-2024:4211
- kernel-rt Rocky Linux 8 4.18.0-553.8.1.rt7.349.el8_10
- kernel Rocky Linux 8 4.18.0-553.8.1.el8_10
rocky linux advisories RLSA-2024:4352RLSA-2024:4211
- git.kernel.org/stable/c/f12554b0ff639e74612cc01b3b4a049e098d2d65 commit
- git.kernel.org/stable/c/14184ec5c958b589ba934da7363a2877879204df commit
- git.kernel.org/stable/c/1bcacd6088d61c0ac6a990d87975600a81f3247e commit
- git.kernel.org/stable/c/f4e6a7f19c82f39b1803e91c54718f0d7143767d commit
- git.kernel.org/stable/c/81de2ed06df8b5451e050fe6a318af3263dbff3f commit
- git.kernel.org/stable/c/05b2b9f7d24b5663d9b47427fe1555bdafd3ea02 commit
- git.kernel.org/stable/c/b4f7a9fc9d094c0c4a66f2ad7c37b1dbe9e78f88 commit
- git.kernel.org/stable/c/c3b26fdf1b32f91c7a3bc743384b4a298ab53ad7 commit
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2021-47236 updated cvss 5.1
kernel: net: cdc_eem: fix tx fixup skb leak
-
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 moreaffected: no fix planned “Out of support scope”
-
Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.8.1.el8_10, kernel 4.18.0-553.8.1.el8_10, bpftool 4.18.0-553.8.1.el8_10, kernel-core 4.18.0-553.8.1.el8_10, kernel-tools 4.18.0-553.8.1.el8_10, python3-perf 4.18.0-553.8.1.el8_10, +15 more Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.8.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.8.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.8.1.el8_10fixed: vendor fix RHSA-2024:4211
-
Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-kvm 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-core 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-modules 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-kvm 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-core 4.18.0-553.8.1.rt7.349.el8_10, +4 more Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-core 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-modules 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-core 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-modules 4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-modules-extra 4.18.0-553.8.1.rt7.349.el8_10, +2 morefixed: vendor fix RHSA-2024:4352
-
Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more Red Hat Enterprise Linux BaseOS (v. 8) kernel-headers 4.18.0-553.8.1.el8_10, kernel-cross-headers 4.18.0-553.8.1.el8_10not affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 y ago
Exploit prediction
0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Affected products
- Linux Linux
Classification
- Weakness
-
- CWE-401 Missing Release of Memory after Effective Lifetime
- Technology feeds
References
-
git.kernel.org
/stable/c/f12554b0ff639e74612cc01b3b4a049e098d2d65
patch
-
git.kernel.org
/stable/c/14184ec5c958b589ba934da7363a2877879204df
patch
-
git.kernel.org
/stable/c/1bcacd6088d61c0ac6a990d87975600a81f3247e
patch
-
git.kernel.org
/stable/c/f4e6a7f19c82f39b1803e91c54718f0d7143767d
patch
-
git.kernel.org
/stable/c/81de2ed06df8b5451e050fe6a318af3263dbff3f
patch
-
git.kernel.org
/stable/c/05b2b9f7d24b5663d9b47427fe1555bdafd3ea02
patch
-
git.kernel.org
/stable/c/b4f7a9fc9d094c0c4a66f2ad7c37b1dbe9e78f88
patch
-
git.kernel.org
/stable/c/c3b26fdf1b32f91c7a3bc743384b4a298ab53ad7
patch
Sources
- CVE List CVE-2021-47236
- NVD CVE-2021-47236
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.